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'''[wiki:GraspExtrasSoftware STARGRASP NTP client]''' |
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[[TracNav(GraspExtrasContents)]] |
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As of SVN revision 4427 of the stage 2 software, the STARGRASP controller has included experimental support for synchronising with an NTP server to provide timing for various events. The client can be started via the '''[wiki:GraspSwControllerCmdNtp ntp]''' command. |
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== Startup Performance == |
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When first started, the NTP client first sets the system time from the first NTP transaction in a single step. Since it cannot make any assumptions about the system's clock drift, it initially starts with a drift correction of zero and attempts to figure out the drift from first principles over successive updates. The result is an initial overshoot that's typically on the order of a couple of milliseconds (the vertical scale below is in usec): |
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[[Image(stargrasp_ntp_startup.png)]] |
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After a couple of minutes, the NTP client typically settles to an NTP offset in the region of 100-200 usec, barring perturbations from the NTP server. |
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== Stargrasp Client: Observed Stability == |
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Show time offset when connected to NTP server via 100Mbit and Gigabit, long-term stability, etc. |
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== Linux NTP Daemon: Observed Stability == |
